某2×660 MW超超临界机组再热汽温低原因分析及优化调整

Cause Analysis and Optimization Adjustment of Low Reheat Steam Temperature o 2×660MW Uiltra-SupercriticalUnit

某电厂2×660 MW超超临界机组锅炉冷再抽汽改造后,低负荷工况下再热汽温偏低,经热平衡分析计算,冷再抽汽量低于设计值将导致再热汽温下降,尤其低负荷时下降明显;在不同负荷下进行冷再抽汽试验,低负荷抽汽量减少,#1炉较#2炉再热汽温下降更为显著。通过相关性分析获得影响#1、2炉再热汽温差的主要因素,并据此作运行优化,低负荷工况下,再热汽温平均提升8℃,调整效果显著。

After cold reheater steam extraction retrofit,the reheat steam temperature of 2×660MW ultra-supercritical unit boiler is lower than the design value under low load.According to thermal balance analysis results,lower reheater extraction steam volume than the design value will result in decreased reheat steam temperature,in particular at low load.The cold reheat steam extraction test was carried out under different loads,and when the amount of extraction steam reduced,the reheat steam temperature of#1 boiler decreased more than that of#2 boiler.Through correlation analysis,the main factors affecting the reheat steam temperature difference between#1 and#2 boiler are obtained,and boiler operation is optimized accordingly.Under low load,the reheat steam temperature was increase by an average of 8C,and theadjustmenteffect is significant.